Assembly device for bus bars



G- H. HART ASSEMBLY DEVICE FOR BUS BARS May 8, 1962 Filed May 29, 1959 3Sheets-Sheet 1 54 FIG. I 5@ I 28 with INVENTOR. GEOPGE H. HA R T ATTORNEY5 May 8, 1962 G. HART ASSEMBLY DEVICE FOR BUS BARS 3 Sheets-Sheet 2Filed May 29, 1959 FIG. 3

FIG. 4

INVENTOR. GEORGE H. HA R 7' ATTORNEYS May 8, 1962 G. H. HART I 3,032,865

ASSEMBLY DEVICE FOR BUS BARS Filed May 29, 1959 5 Sheets-Sheet 3 n I# II/ I 42 /Z M a: /4

INVENTOR. FIG. 9 w m A? GEORGE H. HART A TTOPNE Y5 United States Patent3,032,865 ASSEMBLY DEVICE FOR BUS BARS George H. Hart, West Hartford,Conn., assignor to The Hart Manufacturing Company, Hartford, Conn., acorporation of Connecticut Filed May 29, 1959, Ser. No. 816,919 13Claims. (Cl. 29203) This invention relates to a manually operableassembly device for the simultaneous attachment of a plurality ofelectrical units such as switches to an improved type of bus bar havingrestricted socket openings.

A primary object is to provide an assembly device for rapid attachmentof electrical units having elongate contacts to bus bars of the typehaving integral center and outer socket forming strips with portions ofthe outer strips restricting the socket opening to the extent that theymust be distorted by pivotal movement of a bus bar about a contact whenpartially inserted in the socket to enlarge the socket opening beforethe contact can be forced completely therethrough. The socket formingstrips are termed jaws herein.

1 A further object is to provide a device for positioning a plurality ofcontact carrying electrical units aligned in relation to one or to aplurality of bus bars and for controlling or manipulating the bus barsthrough paths of movement in respect to the contacts during a unitarymanually controlled operation, in a manner rapidly and effectively toaccomplish the clamped engagement of the bars to the contacts of theunits.

A still further object is to provide an assembly device which is simpleto operate; requires a minimum of operator training for reset from onework pattern to another; is self-contained and portable in that itrequires no auxiliary equipment and may be moved by one person tovarious Work stationsis sufliciently rugged to withstand rough handling;insures accurate performance and trouble-free service life; andsubstantially decreases assembly time and costs.

Other objects will be in part obvious and in part pointed out more indetail hereinafter.

The invention accordingly consists in the features of construction,combination of elements and arrangement of parts which will beexemplified in the construction hereinafter set forth and the scope ofthe application of which will be indicated in the appended claims.

In the drawings:

FIG. 1 is a fragmentary top view of an assembly device constructed inaccordance with the invention.

FIG. 2 is a fragmentary end view of the device of FIG. 1.

FIG. 3 is an enlarged fragmentary view, partly in elevation and partlyin section, taken along line 3-3 of FIG. 1.

FIG. 4 is an enlarged fragmentary top view of the device of FIG. 1. 1

FIG. 5 is an enlarged cross-sectional view taken along 5-- 5 of FIG. '1.

FIG. 6 is an enlarged fragmentary view similar to FIG. 5 but with someof the parts omitted.

' FIG. 7 is an enlarged fragmentary cross-sectional view substantiallyalong the line 77 of FIG. 1, but showing dotted an electrical unit andbus bars in a position of final assembly.

FIG. 8 is a top plan view of a bus bar of the type with which thisinvention is concerned; and

FIG. 9 shows in side elevation a bus bar fragment of FIG. 8.

The improved bus bar shown in FIGS. 8 and 9 is of the type described andclaimed in a pending U.S. application, Serial No. 697,683 filed November20, 1957, now

ice

Patent No. 2,981,926. Such a bus bar, generically designated 10, isfabricated from metal stock 11 which may be a copper strip cut andformed in areas spaced along the strip to providesets of jaws to receiveand clamp fiat elongate contacts transversely of the bar. Each set ofjaws is formed by two longitudinal slits made to define a center strip12 separated from marginal strips 14 on either side thereof andlaterally offset from the major plane of the bar to form a pair of lowerjaws as viewed in FIG. 9. The center strip has a mid-portion laterallyoffset in the opposite direction to form a top jaw, the three jaws thusformed defining a contact receiving socket transversely of the bar. Themid-portion of each strip 14 is bent diagonally toward the strip marginat 16, FIG. 8, to form a lip, the outer margin of which is insubstantial alignment with the main plane of the strip stock.

The jaws thus formed represent a substantial improvement overconventional bus bar jaws, but because the liplike portions 16 restrictpassage of a contact between the outer and center jaws, the contact mustfirst be inserted between one of the outer jaws and the center jaw, withthe end thereof abutting the inner margin of the olfset outer jaw, inwhich position the bus bar may be pivoted against the contact to spreadthe first two mentioned jaws and thus open the socket to allowprojection of the contact past the second outer jaw and through thesocket. While the clamping forces exerted by such jaws against a contactprojected therethrough greatly exceed comparable forces of conventionaljaws, certain difiiculties are encountered in assembly of electricalunits to such bars and manual assembly has proved a difficult andtedious operation. The present invention permits a plurality ofelectrical units arranged in a pre-set pattern and each provided withcontacts, rapidly to be attached to a plurality of bus bars having theabove-described improved jaws, by a unitary manually controlledoperation easily accomplished by persons of limited skill.

As best shown in FIGS. 1 and 2, a press type assembly device includes abase 20 having a pair of upright posts 22 and 24 at the back thereof asviewed in FIG. 1. The posts are provided with aligned bearings throughwhich shafts 25 project, the shafts being fixed to the ends of a loweroffset portion 26 of a pressure plate 28, to mount the plate for manualpivoting by handle 30, from the vertical heavy line position of FIG. 2to the horizontal dotted line position shown. Compression springs 32encircle extended portions of each shaft 25, laterally of the bearings,with one end of each spring anchored to the bearing and to the oppositeend to the shaft to bias the pressure plate vertically against thecounter-bias of bus bar positioning plates carried by each of thepositioning blocks, in spring urged engagement with the lower offsetportion of the pressure plate, as more fully described below.

Base 20 is provided longitudinally with a pair of inverted T slots 34and 36 and an intermediate guy lug slot 38 to receive, respectively, theheads of clamp bolts 39 and guy lugs such as 41 carried by a pluralityof electrical unit and bus bar positioning blocks, such as blocks 40 and42, and bus bar centering blocks such as 44 and 46, both type blocksbeing adjustably positionable and clamped in spaced relationlongitudinally of the base as later described. Pressure plate 28 issimilarly provided with T slots 48, 50 and a guy lug slot 52 forpositioning a plurality of press blocks 54, 56 for pressure engagementwith electrical units held by the positioning blocks during operation ofthe device.

The fragmentary top view of FIG. 1 shows the various fixtures set up onthe left side of the base for assembly of two electrical devices, suchas switches, to three spaced bus bars. The right side of the base mayhave fixtures set up in an identical manner for like assembly ofadditional electrical units to another separate set of bus bars duringthe same operation, hence the invention can be fully described byreference only to the apparatus associated with the left side of thebase. Alternately, the device may be set up for assembly of four or moreelectrical units to a single set of longer bus bars; for example, of alength to extend longitudinally over a major portion of the base.

Referring to FIG. 1, it will be noted that positioning blocks 49 and 42are not of identical construction, but they both receive and position,in transverse parallel grooves Provided therein, a plurality of busbars, three bars being simultaneously attached to electrical units bythe device shown. The bus bar sockets are accurately positionedtransversely of the blocks by fingers 45 extending inwardly of centeringblocks 44 and 46 to center the strip-like bars therebetween. The firsttwo bus bars are loosely received in an upright position in the reartransverse grooves (those nearest the pressure plate), while manualpositioning of a third or front bus bar in its groove actuates controlmechanism described below automatically to position and clamp all threebars inclined in respect to the block grooves with their socketspositioned to receive the tips of the unit contacts therein. Eachpositioning block is upwardly open and contoured by removable sideplates 35, 37 to receive a contact carrying electrical unit 43 and guideit in a manner to first position its contacts partially extended intothe bus bar sockets, and to later guide it as its contacts are urgedcompletely through the sockets.

With the units in the positioning blocks as shown in FIG. 6, and thecontacts thereof between the upper and center jaws of the bus bars, thebars are simultaneously pivoted against the back vertical walls of theblock grooves by bus bar control plates as the pressure plate islowered, the bar jaws being spread by the partially inserted contacts,around which the bars must pivot as they are swung to the vertical. Withcontinued swing of the pressure plate, the units 43 are forceddownwardly by press blocks 54, 56 carried by the pressure plate, withtheir contacts being thus urged under pressure through the bus bar jawsas shown in FIG. 7.

A positioning block of the type numbered 42 is shown in FIGS. 3 and 4,with FIG. 5 showing the type numbered 40. Each block has the same body49 with lateral shoulders 51, bored to receive Allen screws 39threadedly engaging T-nuts 39a to permit adjustability from above thebase by an Allen wrench. Each upwardly open block chamber has a bottomwall transversely channeled to define lands and grooves, as shown inFIGS. 1 and 6, the three parallel grooves 53, 55, 57 being of equaldepth. A deeper groove 58 receives dowels 66, extending downwardly fromthe units 43 as shown in FIGS. 6 and 7. The grooves of the severalblocks are in alignment longitudinally of the base to receive the busbars and dowels, respectively. Each block has thus formed therein spacedpairs of lands 72 and 74, one at each side of the block, a pair of rearshoulders 75, and a pair of small forward lands 77, with grooves 53, 55,and 57 therebetween. While the blocks are identical in the aboverespect, they differ in a manner described below as to bus bar controlelements slidably mounted transversely of the lands and grooves.

As shown in FIG. 1, block 40 has a cam plate 63, slidably mountedtransversely of the bar grooves and spaced inwardly of the left side ofthe block. Block 42 has an identical plate 69 spaced inwardly of itsright side. Each plate, as shown in FIG. 7, is biased back toward thepressure plate by a spring 71, the plates having upwardly open groovesshaped to register with the block grooves when the plate is held in aforward position against the pressure of its spring 71 by the pressureplate when vertical, as shown in FIGS. 2 and 5, the plates being movedto the FIG. 7 position by' springs 71 as the pressure plate is swungtoward the horizontal.

Block 42 carries a bus bar canting plate 70 slidably mounted laterallyof cam plate 69 and latched to the block when positioned as shown inFIG. 3 by a stop 74 carried by a pin 78, slidable vertically of thefront bar groove and urged upwardly by a coil spring 79. A pawl 73pivots about a pin 73a, fixed to the block and has a loose pinconnection 73b to cam plate 69. The top of plate 70 is provided withlands and grooves for registry with corresponding lands and grooves ofboth the block and the cam plate when in the latched position of FIG. 3,but the left walls of the grooves are diagonally cut as at 76. Plate 70is biased to the right as viewed in FIG. 3, by leaf spring 81, but sincelatched to the block by stop 74, the action of that spring is arresteduntil pin 78 is depressed to a position flush with the base of the blockgroove to move stop 74 downwardly and clear of a latching shoulder 80defined by a notch 83 in the canting plate 70. When unlatched, plate 70moves to the right sufiiciently to tilt the bus bar as described below,and is returned to the FIG. 3 position as cam plate 69 is recarnrned tothe left, by pawl tooth 73c which engages a shoulder 70a in plate 70 toconnect plate 70 to cam plate 69 for return of plate 70 to the latchedposition.

Block 40 has a somewhat different bus bar control plate 82 slidablymounted along its left side laterally of cam plate 68 and biased to theleft by spring 84 as shown in FIG. 5. Plate 82 also has upward lands andgrooves registerable with those of the block when moved to the rightfrom the position shown against the bias of spring 84. The lands ofplate 82 form laterally projecting hook portions 86 and its grooves aredefined by vertical walls at the left and diagonal Walls at the right,as shown in FIG. 5, whereas the corresponding grooves of plate 70 havevertical walls at the right and horizontal walls at the left, as shownin FIG. 3. There is no interlinking connection between plate 68 andplate 82 of block 40. Each block is provided with a pair of resilientlymounted rests 96 and 89 which serve both to properly support theelectrical units 43 in the block chambers with their contact tipsdisposed as shown in FIG. 6, and as knockout blocks to raise the unitsand attached bars as the final step in the assembly operation. Rests 96,89 are horizontally supported by slidable pins 91 and 93 having stops95, 97 and biased upwardly, respectively, by coil springs 99 and 101.

Detailed operation of the device is as follows:

With pressure plate 28 in the fully vertical position of FIG. 2, anadjustable limiting stop 88 engages a stop post 90, with a cam strip 92,marginally of the inner surface of offset plate portion 26 positioned tohold cam plates 68 and 69 forced against their spring 71 with the camplates depressed and the grooves thereof in registry with the bargrooves. When so positioned, plate 70 is latched to block 42, as shownin FIG. 3, and plate 82 is biased by spring 84 into the FIG. 5 positionwith the inclined groove walls extending partially into the blockgrooves. The device is now ready to receive the bus bar, a strip at atime, the manual loading operation starting from the back groove, thebus bars being placed in the grooves, with the center bar jaws towardthe operator. The jaws defining the bar sockets are properly positionedinthe blocks as they are dropped into the slots between the centeringfingers 45. The first two bars are loosely received and may assumeeither a vertical or a diagonal position, but as the third bar isdropped into the front slots of the blocks, the operator depresses itagainst pin 78 to unlatch plate '70 which springs rearwardly (toward thepressure plate) under the urge of spring 81 with the inclined groovewalls thereof forcing the bars into clamped engagement with the inclinedwalls of plate 82 and the upper bar margins recessed under thefinger-like. hooks 86 firmly to hold the bars in the grooves, aspositioned as shown dotted in FIG. 6. v

The electrical units 43 are then dropped, contacts down, into the blockchannels in which they are loosely received but properly guided to causetheir contacts 83, 85, and 87 to project between the upper and centralstrip of each bar jaw, with units supported, when so positioned, onrests 96, 89. The operator then swings pressure plate downwardly byhandle 30 toward the dotted horizontal position of FIG. 2. During earlystages of this final operation, cam strip 92 swings outwardly of camplates 68 and 69 to allow biasing springs 71 to move their plates towardthe vertical rear groove Walls thereof and pivot the bars from theinclined FIG. 6 to the vertical FIG. 7 position with the bus bars heldfirmly clamped vertically in the block grooves between the verticalgroove Walls 65, 65a and 65b and the lower vertical walls of the blockgrooves. As the bus bars are thus pivoted simultaneously with theoutward swing of the cam strip 92, plate 82 is pushed back clear of thegrooves against the bias of its leaf spring 84 by the substantiallystronger counter-bias of coil spring 71 to remove the inclined barpositioning Walls of plate 82 from the block grooves, thus permittingvertical bar clamping as above described.

As the pressure plate continues its swing to the horizontal, pressblocks 54, 56 engage upper surfaces of the units 43, and force themdownwardly of the blocks, depressing rests 89, 96 and forcing contacts83, 85, 87 completely through the bus bar jaws, as shown in FIG. 7, tocomplete the attachment of the bars to the units. As the pressure bar isswung back to vertical, and the press blocks move out of engagement withthe units, rests 89, 96 push the units upwardly under urge of theirbiasing springs, and the attached bus bars are forced out of the groovesto facilitate removal of the unitary assembly. As the pressure plateapproaches vertical, cam strip 92 resets the device for the next cycleof operation by forcing cam plates 68 and 69 forwardly to again registerthe plate grooves with the block grooves, such depression of cam 69causing pawl 73 thereof to engage and move plate 70 forwardly forre-latching as shown in FIG. 3.

While only one of each type of bar positioning block is shown anddescribed above, two or more of each type block are often used forsimultaneous attachment of four or more electrical units to bus bars.When three units are to be attached, it is preferable to set up thedevice with a type 42 block spaced on opposite sides of a type 40 block.To facilitate set-up for any desired pattern of assembly, a measuringrule 104 is fixed to the top of base 28 along the front margin thereof,and an identical rule 186 is mounted, With its scale in longitudinalregistry therewith to the front surface of the pressure plate adjacentthe top of the press blocks, as best shown in FIG. 6. Each press blockis provided with .a scale pointer 108 overlying rule 106 and each frontwall of a positioning block carries a rule line, as indicated by groove110, FIG. 4. Corresponding scale settings of the pointers and markinglines accurately establish vertical registry between each positioningblock and its co-operating press block.

As will be apparent to persons skilled in the art, various modificationsand adaptations of the structure above described will become readilyapparent without departure from the spirit and scope of the invention,the scope of which is defined'in the appended claims.

I claim:

I. A press-like assembly fixture for attaching electrical units havingstrip-like contacts to an elongate bus bar having transverse socketsformed by jaws and in which socket restricting portions extendlongitudinally thereof, said fixture comprising a base, a pressure platemounted for movement in respect to the base, positioning means supportedon said base for positioning a bus bar lengthwise thereabove, clampingmeans supported on the base and transversely oriented with respectthereto and operatively associated with said positioning means forclamping said bus bar in a transversely inclined position relative tosaid base, means on the base for positioning a plurality of electricalunits above the bus bar with tip portions of said contacts extendingvertically relative to said base into said sockets and underlying saidrestricting portions, pivoting means supported adjacent the base andoperatively associated with said bus bar positioning means and saidclamping means and connecting said pressure plate for actuation therebyto pivot the bus bar about the contacts and into a position of alignmenttherewith, whereby said restricting portions are forced laterallyoutwardly of said sockets, and means on said pressure plate to forcesaid contacts through the bus bar sockets.

2. An assembly device for forcing elongate contacts of electrical unitsthrough bus bar sockets formed transversely of the bar by longitudinallyextending jaws having socket restricting portions which must be forcedlaterally by pivotal manipulation of the contacts to permit contactextension therethrough, said device comprising longitudinally extendingsupport means for disposing a plurality of bus bars lengthwise on edgeand in parallel spaced relation, means mounted adjacent said supportmeans for positioning a pluarlity of contact carrying units with theircontacts overlying the sockets formed in the supported bus bars, meanson said support means and transversely oriented with respect thereto forpositioning and clamping said bars in a transversely inclined positionrelative to said support means with the bar jaws thereof positioned toallow the contact tips to enter the sockets and underlie saidrestricting portions, pivoting means mounted adjacent said support meansfor spreading the bar jaws by pivoting the bars from said inclinedposition about said contact tips into alignment with the contacts,whereby said restricting portions are forced laterally outwardly of thesocket, means on said support means for clamping said bars in saidposition, and forcing means mounted adjacent said support means forforcing the contacts of the units through the spread bar jaws.

3. The device of claim 2 wherein said support means comprisespositioning blocks provided with longitudinally extending bus barreceiving grooves, and said means for positioning and clamping said barscomprising a bus bar control plate slidably mounted on each block fortransverse movement relative to the block grooves, each plate beingprovided with grooves registrable with the block grooves, and with cammeans connecting said forcing means and said control plate and operableby said forcing means for moving said control plate from a position ofregistry of the grooves thereof with the block grooves to a position ofnon-registry therebetween to clamp the bus bar in the block grooves.

4-. In a device for attaching an electrical unit having an elongatecontact to a bus bar having a transversely positioned socket defined byjaws and in which a longitudinally extending socket restricting portionmust be forced laterally outwardly to enable the socket to receive thecontact, support means for holding the bar along its length with thesocket positioned to receive the contact, means on said support meansand operable therewith to position the unit with the contact thereofdisposed partially within the socket and underlying said restrictingportion, means on said support means for pivoting the bar about thecontact from the contact receiving position to force the socketrestricting portion laterally outwardly of the socket and thereby alignthe socket with the contact, and means mounted adjacent said supportmeans for urging said contact into said spread socket.

5. In a device of the character described, an electrical unit and busbar positioning block comprising a base provided with an upwardly openchamber for receiving the electrical unit and a groove extending throughthe block for supporting a bus bar below the chamber a pair of centeringblocks, each centering block located laterally and on opposite sides ofsaid positioning block and containing means for centering a bus barextending therebetween and supported by said groove, a cam plateslidably mounted in said block for transverse movement relative to saidblock groove, said plate having a groove registrable with the blockgroove, a positioning plate slidably mounted on said block fortransverse movement relative to said block groove and having a grooveregistrable with the block groove and including an inclined wall,resilient means connecting said cam plate and said block and biasingsaid cam plate toward a direction of non-registry of its groove with theblock groove, and resilient means connecting said positioning plate andsaid block and biasing said positioning plate in the opposite directionfor non-registry of its groove with the block groove with the inclinedwall thereof partially restricting the block groove.

6. In a device for attaching elongate bus bars to electrical unitshaving strip-like contacts, a longitudinally extending base, a pluralityof blocks for positioning the elongated bus bars and electrical unitsand mounted in aligned longitudinal spaced relation on said base, alongitudinally extending pressure plate pivotally mounted on said base,a plurality of press blocks mounted in aligned longitudinal spacedrelation on said pressure plate and in transverse alignment with saidpositioning blocks and movable by pivotal movement of said pressureplate into registry with said blocks, each positioning block beingprovided with parallel transversely spaced grooves in longitudinalalignment with corresponding grooves of the other blocks along the baseand dimensioned for supporting the bus bars on edge along their length,each said block being formed with an upwardly open vertical chamberabove the grooves for the reception of electrical units, means on saidbase and connecting said pressure plate and associated with each blockand operable in response to pivoting of said pressure plate to aposition of non-registry between said positioning blocks and pressblocks to move and clamp said bus bars along their length to atransversely inclined position in respect to the vertical chambers, andfurther means on said base and connecting said pressure plate andassociated with each block and operable in response to the pivoting ofsaid pressure plate from said position of non-registry toward a positionof registry between said positioning blocks and press blocks to move andclamp the bus bars along their length into transverse vertical alignmentwith said block chambers.

7. In a device for attaching bus bars to electrical units, a base, aplurality of positioning blocks aligned on said base, each blockprovided with an upwardly open chan1- her for the reception of anelectrical unit, each block chamber having at the bottom thereof aplurality of spaced parallel grooves for the reception of bus bars,inclined wall means on the base and associated with said blocks andextending into said grooves for positioning and clamping bus bars in aninclined position relative to said upwardly open chamber, vertical wallmeans on the base and associated with said blocks for subsequentlypositioning and clamping the bus bars vertically relative to saidchamber, a pressure member mounted on said base to pivot from a positionvertically thereof to a horizontal position adjacent said positioningblocks and above said chamber, and cam means cooperatively connectedbetween said pressure member and said inclined wall means and saidvertical wall means for actuating said inclined wall means by verticalpositioning of said pressure member and for actuating said vertical wallmeans in response to the pivoting of said pressure member from thevertical toward the horizontal position.

8. In a device for attaching the strip-like contact of an electricalunit to a bus bar having a transverse socket formed therein and definedby a center jaw and a pair of marginal jaws laterally olliset from thecenter jaw, longitudinally extending support means for supporting theelongated bus bar on edge along its length, means on said support meansand transversely oriented with respect thereto for holding the bar in atransversely inclined position relative to said support, means on saidsupport means for positioning the electrical unit above said bar withthe contact extending downward between and in contact with one of themarginal jaws and the center jaw of the socket, pressure means mountedadjacent said support means and movable into engagement with theelectrical unit, and pivoting means connecting said pressure means andsaid bus bars and operable by movement of the pressure means to pivotsaid bars about said contacts from the transversely inclined position toa position of transverse alignment with said downwardly extendingcontact where by said jaws are spread and said contact may be urgedbetween the center and both marginal jaws by force exerted on said unitby said pressure means.

9. In a fixture for attaching electrical units having strip-likecontacts to bus bars provided with transverse sockets, a longitudinallyextending base, a member pivotably attached to said base, a plurality ofpositioning blocks mounted on said base, each said block being providedwith a longitudinally extending groove leading upwardly into an openchamber, said blocks being positioned on the base to align said groovesto receive a bus bar positioned to extend between the blocks, the openchamber of each block being adapted to receive an elec trical unit withits contact extending downwardly within the transverse sockets of thebus bar, means on the base and associated with said blocks forpositioning said bar with the transverse sockets inclined upwardly inthe grooves, forcing means on the base for forcing said bars from thesocket inclined position to position the sockets vertically, actuatingmeans connecting said member and said forcing means for actuating saidforcing means in response to the pivoting of said member, means on saidmember for forcing the electrical unit toward said groove and saidcontact through a bar socket when said socket is vertically positioned,and knockout means in said blocks for urging said bus bar and attachedunit upwardly upon deactivation of said forcing means.

10. In a device for attaching an electrical unit to a bus bar, apositioning block comprising a base, said base being formed with anupwardly open chamber to receive the electrical unit and a grooveextending transversely through the block for receiving the bus bar belowthe chamber, said groove opening upwardly into the chamber, a cam platelongitudinally disposed and slidably mounted in said block for movementtransversely of said groove, said cam plate having a groove registrablewith the block groove, said groove in said positioning plate having aninclined wall, resilient means connecting said block and said cam plateand biasing said cam plate in one direction for non-registry of thegroove thereof with the block groove, resilient means connecting saidblock and said positioning plate and biasing said positioning plate inthe opposite direction for non-registry of the groove thereof with theblock groove, latch means in said block and latching said positioningplate against the biasing of its resilient means with the groove thereofin registry with the block groove, and means in said block adjacent thebottom of the block groove and connecting said latch means for releasingsaid positioning plate with resultant movement thereof under the biasingurge of its resilient means to a position of non-registry of its groovewith the block groove to move the inclined wall into a position 7partially to restrict the block groove.

blocks to position the bus bars therein extending between the blocks inan inclined position with respect to the base when said pressure plateis positioned vertically, means mounted on the base adjacent saidpositioning blocks and connecting said pressure plate to swing said busbar from said inclined position to a vertical position relative to saidbase responsive to movement of said pressure plate toward a horizontalposition, said lastmentioned means including a cam plate carried by eachblock with portions extending toward the pressure plate, spring meansbiasing said cam plate into contact with a portion of said pressureplate when said pressure plate is vertically positioned, said portion ofsaid pressure plate swinging outwardly to allow the cam plates to moveunder urging of their spring means as the pressure plate is tilted fromthe vertical, and repositioned responsive to its return to the vertical.

12. In a device for attaching electrical units having contact strips tobus bars provided with transverse sockets having socket restrictingportions therein, a base, a pres sure plate pivotally mounted on thebase for movement from a vertical to a horizontal position with respectthereto, holding means supported on said base and movable in response tocontact by one of the bus bars therewith to a position holding andclamping the bus bars with the sockets transversely inclined relative tosaid base, means on the base for holding electrical units above the busbar with their contact strips projecting downwardly within thetransverse socket and underlying the socket restricting portions, meansconnecting said pressure plate and said holding means and operable bymovement of said pressure plate from the vertical toward the horizontalposition to pivot said bus bars about the engaged contact strips into avertical position relative to said base, whereby said restrictingportions are moved laterally outwardly of the sockets, and means cantedby said pressure plate for pressing the electrical units downwardly toproject the contacts through the sockets to complete the assembly of thebus bars on the unit contact strips.

13. The device of claim 12 in which said bus bar holding means and saidmeans for holding the electrical units comprises a plurality of blocksfixed in aligned spaced relation to said base and are provided with busbar receiving grooves in parallel spaced relation at the bottom ofupwardly open unit positioning chambers in each block, each groove hasside walls contoured to permit a bus bar to be held in an inclinedposition relative to the base and in a vertical position relative to thebase, said means connecting said pressure plate and said holding meansis a cam slidably supported by each said block for transverse movementrelative to the grooves, each cam is biased by resilient meansconnecting it to its associated block to maintain the bus bars clampedvertically of the grooves, said pressure plate provides a stop surfaceand said cam is depressed against its resilient means by said stopportion of the pressure plate when said pressure plate is in thevertical position to permit the bus bars to be inclined in the grooves,and said stop portion is swung outwardly with movement of the pressureplate toward the horizontal with said cam being moved by its resilientmeans and thereby moving the bus bars from said inclined to a verticalposition.

References Cited in the file of this patent UNITED STATES PATENTS1,173,214 Postel Feb. 29, 1916 1,975,422 Hellenbroich Oct. 2, 19342,324,009 McDonough July 13, 1943 2,685,126 MacPheat Aug. 3, 19542,820,283 Anderson Jan. 21, 1958

